Listed below are the Disciplinary Core Ideas (DCI) for Physical Science and bullet points for their specific grade band progression.

PS1: Matter and Its Interactions

PS1.B: Chemical Reactions

Primary School (K-2)

Heating or cooling a substance may cause changes that can be observed. Sometimes these changes are reversible, and sometimes they are not.

Elementary School (3-5)

When two or more different substances are mixed, a new substance with different properties may be formed.

No matter what reaction or change in properties occurs, the total weight of the substances does not change. (Boundary: Mass and weight are not distinguished at this grade level.)

Middle School (6-8)

Substances react chemically in characteristic ways. In a chemical process, the atoms that make up the original substances are regrouped into different molecules, and these new substances have different properties from those of the reactants.

The total number of each type of atom is conserved, and thus the mass does not change.

Some chemical reactions release energy, others store energy.

High School (9-12)

Chemical processes, their rates, and whether or not energy is stored or released can be understood in terms of the collisions of molecules and the rearrangements of atoms into new molecules, with consequent changes in the sum of all bond energies in the set of molecules that are matched by changes in kinetic energy.

In many situations, a dynamic and condition-dependent balance between a reaction and the reverse reaction determines the numbers of all types of molecules present.

The fact that atoms are conserved, together with knowledge of the chemical properties of the elements involved, can be used to describe and predict chemical reactions.

This is a table of the Disciplinary Core Ideas
of Physical Science. If
coming from a Standard the specific bullet point used is highlighted
and additional performance Expectations that make use of the
Disciplinary Core Idea can be found below the table.
To see all Disciplinary Core Ideas, click on the title "Disciplinary Core Ideas."